Motor-controller.



C. W. YERGER. MoToR CONTROLLER.

APPLICATION FILED JUNE 22, 19|]- )ww l M uw TN NQ uw WWUMM! hw W 9, .7 m N y ,Y w WJ 1...... /Am Nm, Vg# ...u 7, v m 5 7 M 6 UNITED' STATES PATENT oEEicE.

CHARLES W. YERGER, OF MILWAUKEE, WISCONSIN, ASSIGNOR T THE CUTLER- HAMMER MFG'. CO., OF MILWAUKEE;.WISCONSIN, A GORPORATION OF WIS- Specification of Letters Patent.

MOTOR-CONTROLLER.

Patented Oct. 19, 1915.

Application led .Tune 22, 1911. Serial No. 634,712.

To all whom it may concern.'

Be it known that I, CHARLES W. YERGER, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Motor-Controllers, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

y invention relates to controllers for electric motors.

One object of my invention is to provide a controller which will enable the use of a motor for different duties with convenience and safety.

A further object vof my invention is to provide a controller which will insure equally good conditions of acceleration of the motor in its performance of different duties.

Further advantages and objects of my invention will be hereinafter setforth.

My invention is particularly applicable to the control of motor-operated elevators where it' is desired to use the same for both passenger and freight duty but is not limited to this particular use or application.

' Heretofore, where it has been desired to use the same motor for both passenger and freight elevator duty it has been found necessary to provide what is commonly termed back-gearing to compensate forV the load variations in the different classes of service. In freight servlce the load conditions are much more severe than 1n passenger service but the speed requirements in the former are much more lax than in the latter. As is well understood by those skilled in the art, by reducing the speed of lift of a given load the power required for lifting is decreased. Hence back-gearing was employed to compensate for varying loads by varying the speed ratio between the load and the motor to protect the motor against overload. This method however, is

open to many objections among which may' ed for different classes of service by mere regulation of electrical means, and in a preferred form of my invention, by the manipulation of but a single switch.

As above stated it should be understood that my invention is not limited to the abovev application but may be used in various other relations and for various other purposes. l

For the purpose of more clearly and fully setting forth the nature and characteristic features of my invention I shall describe the controller diagrammatically illustrated in the accompanying drawing. It should be understood, however, that the embodiment'of my invention shown in the accompanying drawing has merely been selected for the purpose of illustration and that my invention is susceptible to embodiment in various other forms. i

rihe controller diagrammatically illustrated in the accompanying drawing is particularly applicable to elevator control.' Accordingly, for the purpose of this explanation, let it be assumed that the motor 1, shown in the drawing, is employed for operating an elevator. Compound wound motors are preferable in elevator service and I have accordingly shown the motor 1 as provided with an armature A, a series field winding F and a shunt field winding f.

In series with the motor armature are the usual starting resistances 1', r r2, and r3,

it of course being understood that any numings 2a, 3a, 4a, 5a, and 6a respectively. In

practice these windings may bey controlled 'in any preferred manner, but for the purpose of illustration I have shown all of said windings connected to a common conductor, controlled by a single pole, switch 7. I have also provided each of the switches with an auxiliary contact, designated by the corresponding reference numeral with the exponent for closing the circuit of the operating winding of the next succeeding switch, whereby said switches are successively energized automatically upon closure of the switch 7. Associated with each of the switches 6, 2, 3, and 4 is a current relay switch, given the same reference numeral as its corresponding switch, with lthe exponent c. Each of these relay switches is adapted to control the circuit of the operating winding ot the next succeeding switch and is provided with an operating winding adapted upon closure of its corresponding switch to be included in the motor circuit. These relay switches serve in a well known manner to temporarily check the progressive operation of the resistance controlling switches upon excessive surges of current in the motor circuit to protect the motor against injury. Of course in practice other protective means and interloclrs to protect the motor may be employed, but it has been deemed unnecessary to disclose any further protective means herein. r1`he foregoing provides means for starting the motor and bringing the same up to normal speed, and as will be hereinafter more clearly and fully set forth short circuits the series field winding of the motor when the motor issubstantiallv brought to normal speed.

1n addition to the above described starting or accelerating means 1 have provided means for weakening the shunt iield winding after the motor has been brought up to a normal speed to further increase the speed thereof. This means includes la resistance 8, in series with the shunt ield winding and normally short circuited by a switch 9. The switch 9 is provided with an operating winding 10, controlled by an auxiliary contact 5b of the switch 5, in such a manner as to be energized only upon closure of said switch 5. To further insure against premature response of the switch 9 1 have provided, in conjunction with the switch 5, a relay switch 5c. This relay switch is in series with the operating winding of switch 9 and has an operating winding adapted upon closure of the switch 5 to be connected in the motor circuit to insure against energization of the switch 9 while abnormal current conditions prevail in the motor circuit.

For passenger elevator service only so much of the controller as has been above described would be utilized and therefore before proceeding further 1 shall describe the mode of operation and tunctionsof so much of the controller. Assume that current is supplied to the motor and to the windings of the various switches from supply lines 15 and 16.. With the several switches in the positions illustrated, the motor would be disconnected from circuit.

To start the motor it is only necessary to close the switch 7 Thereupon circuit is closed Jfrom main line 15 byconductor 17 through the operating winding of main switch 6 to conductor 18 and thence to main lline 16.

The establishment of this circuit causes the switch 6 to respond and close the motor circuit as follows :--From main line 15 through switch 6 by conductor 19 through the winding of relay switch 6c by conductor 20 through all of the resistances 1*, 7', r2 and 113 by conductor 21 through the series ield winding F of the motor by conductors 22 and 23 through the motor armature by conductors 24 and 25 to main line 16. Also circuit is closed from switch 6 by conductors 27, 28 and 29 through the shunt eld winding f of the motor by conductor 30 through switch 9 and conductor 31 to conductor 25. The motor is thus started but with all of the starting resistancesin circuit. However,upon closure of switch 6 the auxiliary contact 6P thereof completes a circuit from switch 6 through relay 6C and thence through the operating winding of the first accelerating switch 2 to conductor 18. 1i' the relay switch 6c is not caused to respond upon closure of the motor circuit, the operating winding of switch 2 would be immediately energized and close said switch. 1f however, the relay switch 6c does respond upon closure of the motor circuit, the circuit through the operating winding of switch 2 will ot' course not be completed until the relay drops its plunger upon the restoration of normal conditions in the motor circuit. The relay 6c and likewise the remaining relays may be adjusted to respond at any desired current values. Upon closure of switch 2 the resistance i" is short circuited, said short circuit extending from switch 6 by conductors 27, 28 and 35 through the switch 2 by conductor 36 through the operating winding of relay 2c by conductor 37 to a point between the resistances o and r. Also upon closing switch 2 through its auxiliary contact 2b completes the circuit of the operating winding of the next accelerating switch 3 through the relay switch 2c. Accordingly said switch 3 cannot respond until the return of the relay switch 2c to closed position in the event that it responds upon closure of switch 2. Closure of switch 3 completes a short circuit around resistance r from conductor 28 through said switch 3 by conductor 38 through the winding of relay 3c by conductor 39 toa point between resistancesr and r2. Closure of switch 3v also completes through its auxiliary contact 3b the circuit of' the operating winding of switch 4 through the relay switch 3 and said switch 4 when closing short circuits the resistance r2. This short circuit `extends from con-v ductor 28 lby conductor 40 through the switch 4 thence through the operating winding of relay 4c by conductor 41 to a point between resistances r2 and r3. Also upon closing switch 4 completes the circuit of the operating winding of switch 5 through its auxiliary contact 4b and the relay switch 4C. Switch 5 in closing short circuits both the resistance r3 and also the Series tield'winding F of the motor. This s hort circuit extends from conductor 28 by conductor 42 through switch 5 by conductor 43 through the winding of relay 5c to conductor 23 and thence to the motor armature as already traced. The purpose and advantage of short circuiting the series eld winding being well understood in the art, it is needless to herein eX- plain the same. Of course the series field need not be short circuited unless desired.

It will thus be seen that closure of control switch 7 first causes completion of the motor circuit and then gradual removal of the resistances 7', 7", 7n2 and 7a3 to bring the motor up to normal speed with the series eld winding short circuited. Likewise it will be seen that this acceleration is governed by the relay switches to protect the motor against excessive surges of current.

Switch 5 upon closing completes through its auxiliary contact 5" a circuit through the relay 5c by conductor 44, through the operating winding 10 of switch 9 by conductor 45, through a switch hereinafter described to conductor 25. This causes energization of the switch 9 which upon responding opens the short circuit around resistance 8 thereby throwing said resistance in series with the shunt field winding f. This of course weakens the shunt field winding of the motor and further increases the speed thereof. The relay 5c in circuit with the operating winding of switch 9 prevents response of said switch until the desired current conditions are established in the motor circuit.

To stop the motor it is only necessary to open the switch 7 whereupon all of the switches previously mentioned will drop out, therebyy disconnecting the motor from circuit. Of course in practice reversing means may be used, but it has been deemed unnecessary to herein.

The controller above described will obviously give the high speed desired for passenger elevator service and duly protect the motor in such service where the load is confined within predetermined limits.

I shall now describe the means for adapting the above controllerl and accordingly the motor to freight or other heavier and more severe duty. This means includes a switch 46 in series with the operating winding of switch 10 and adapted upon use of the motor for the heavier and more severe service mentionedto be opened to prevent response of the switch 9. -This insures the maintenance of the short circuit around the resistance 8 and consequently full shunt eld strength, and a reduction in the maximum -speed of the motor. Under these conditions the motor can obviously be safely used to. lift a greater load than under the previously described maximum speed condishow or describe the same tions since the power thus required at the speed obtainable would be no greater. However, in this heavier and more severe duty more power is required for starting the motor and bringing the same up to speed than in the previously considered service. To meet these conditions I have provided an auxiliary set of resistances 74, 775, 7', and 77 which I connect in parallel to the resistances 7. 7", r2 and 7'3 respectively. Provision of these parallel resistances obviously permit a greater flow of current to the motor during the starting period. Equally obviously the degree of increase of current is dependent upon the value of the auxiliary resistances, and accordingly may be regulated as desired. For connecting these auxiliary resistances in circuit any suitable formof switch either manual or automatic may be employed. I have shown a double pole knife switch 47 and have provided an interlock between said knife switch and switch 46, whereby when switch 47 is closed the switch 46 is opened and conversely when the switch 47 is opened, the switch 46 is closed. This interlock comprises a lug 48 on the knife switch adapted when the same is opened to engage and close switch 46 which is normally biased to open position by a spring 49. Of course in practice any other desired form of interlock may be employed. Thus I positively insure against ield weakening when the switch 47 is thrown in to adapt the controller to the heavy and more severe service mentioned.

When desired to use the motor for freight elevator or like service, it is merely neces-v sary to close the switch 47 and operate the controller as above described. The additional circuits established under these 'conditions are as follows z--Upon closure of main line switch 6 the current divides at the stationary contact of said switch, one branch extending as above described, while the other branch extends by conductor 50 through the. resistance 7-4 by conductor 51 to the left hand blade of switch 7, thence through said blade and by conductor 52 through resistances 7'5 and 76by conductor 53 through the right hand blade of switch 47 .by conductor 54, through the resistance 7"7 to conductor 2l where it reunites with lll@ the other branch. Thus'the resistances 74,

75, 7'6 and 7'7 are connected in parallel to the resistances 7', 7i', 7'2 and 78 as above set forth and with the results aforesaid. Upon Closure of switch 2 to short circuit resistance 7l a short circuit is also established by said switch around the resistance 774. This short circuit is established from the left hand terminal of resistance 7'4 by conductors 50, 28 and'35 through switch 2 by conductor 36 and conductor 55 to the intermediate contact of the left hand blade of switch 47, thence to conductor 5l and the right hand terminal of resistance 1'". Closure of switch 3 establishes in addition to the short circuit around the resistance r a short circuit around the resistance 1'5. This short circuit extends from conductor 28 through switch 3 by conductors 38 and 56 to a point between the resistances 115 and r6. Closure of switch et in addition to short circuiting resistance r2 also short circuits resistance r6. This latter short circuit extends from conductor 28 by conductor 40 through the switch L by conductors 57 to the intermediate contact of the right hand blade of switch 47, thence through said blade to conductor 53 leading from resistance r6. Switch 5 in addition to short circuiting resistance r3 and the series field winding of the motor also short circuits resistance 17. This latter short circuit extends from conductor 28 through the switch 5 by conductor 13 through the coil of relay 5C which of course now serves no purpose, to conductor 23, and thence to the motor armature.

lt will thus be seen that 1 am enabled to control the auxiliary resistances without the necessity of providing any additional control switches. lit will further be observed upon tracing the circuits of these auxiliary resistances that each is connected in parallel and not in series with the current relay governing its corresponding1 control switch. Accordingly only the current traversing the parallel path will pass through the relayT windings and thus the flow of current through said windings will remain substantially unchanged. Therefore the relays will respond under substantially the same current conditions as before thereby insuring equally good and safe conditions of acceleration under the heavier load condition.

What 1 claim as new and desire to secure by Letters Patent is as follows l. The combination with an electric motor, of accelerating means therefor' and electrical means for compensating for load variations in starting to thereby adapt said accelerating means to changes in the load on the motor.

2. The combination with an electric motor, of power controlling means therefor toaccelerate the same by successive increments of power and means to adjust said former means to diiierent load conditions by varying the individual values of said power increments.

3. 1n a controller for electric motors in i combination, a plurality of resistances, a

4. In a controller for electric motors in combination, a plurality of resistances, a plurality of the separately actuated switches lfor controlling said resistances to gradually ments to compensate for the effect of load variations on said motor in starting.

6. lin a controller for electric motors in combination, a plurality of resistance sections, a plurality of separately actuated switches each adapted to short-circuit one of said resistance sections to accelerate the motor, a plurali-ty of auxiliary resistance sections anda single switch for connecting said auxiliary resistance sections to said first mentioned resistance sections, each of the former in parallel with one of the latter.

7. 1n a controller for electric motors, in combination, automatic accelerating means for the motor, electroresponsive means for arresting the operation of said first mentioned means upon the occurrence of abnormal conditions in the motor circuit, and

.means independent of said. accelerating means for varying the amount of current supplied to the motor by said accelerating means without affecting the adjustment of said electroresponsive means.

8. ln a controller for electric motors in combination, means for accelerating the moto:` in steps, means responsive to current conditions in the motor circuit for coni trolling said accelerating means, and meansl for varying the amount offcurrent supplied through said accelerating means without varying the flow of current through said current responsive means.

9. In a controller for electric motors, the combination with resistance varying means for gradually accelerating the motor, means responsive to current conditions in the motor circuit for governing the operation of said resistance varying means, and means for varying the resistance controlled by said resistance varying means without varying the current iiow through said current responsive means.

10. In a motor controller in combination, a resistance in the'motor circuit, a switch for controlling said resistance, a relay device for governing the operation of said switch, said relay having an operating winding connected in the motor circuit .in series with said resistance and a second resistance i with said resistance, and a ysecond resistance` adapted to be connected in parallel to said first mentioned resistance and-the operating winding of said relay device to increase the ow of current in the motor circuit without increasing the flow of current through the operating winding of said relay device. A

11. In a motor controller in combination, a resistance in the motor circuit, a switch for controlling said resistance, a relay device for governing the operation of said switch, said relay having an operating winding connected in the motor circuit in series adapted to be connected in parallel to said first mentioned resistance and the operating Winding of said relay device to increase the flow of current in the motor circuit without increasing the flow of current through the operating winding of said relay device said second resistance being controllable by said switch.

12. In a controllerfor electric motors in combination, a plurality of resistances in the motor circuit, a plurality of switches for gradually removing said resistance, a plurality of relay devices for governing the operation of said switches, each of said relay devices having an operating winding connected in series with the motor, a second resistance, and meansv for connecting said second resistance in parallellwith said first mentioned resistance' to be gradually removed simultaneously therewith by said switches, the flow of current through the windings of said relay devices being un-v altered by the connections of said second resistance.

13. In a controller for electric motors in combination, means for gradually starting the motor and after bringing the motor up to normal speed to further accelerate the same, and means forincreasing the power available for starting the motor vand restricting the speed obtainable with said first mentioned means. l

14. In a controller for electric motors in combinatiommeans for starting the motor and regulating the speed thereof, means for regulating the power available for starting the motor by said rst mentioned means, and means for restricting the speed obtainable with said first mentioned means, 'said last two mentioned means being interlocked to insure operation of one upon operation of the other.

15. In combination, an electric motor, means for accelerating said motor to normal speed and thereafter weakening the field thereof for further acceleration, means for varying the amount of current supplied to themotor by said first-mentioned means,

and an interlock between said means forl vrendering said rst-mentloned means 1neffective to weaken the field of said motor under predetermined conditions.

16. The combination with an electric motor, of automatic accelerating means therefor controlled in its operationv by the electrical conditions in said motor, and means associated with said accelerating means to electrically compensate for the effect of load 'variations on said motor in scribed my name in the presence of two witnesses.

v CHARLES W. YERGER.

Witnesses:

` LoUIs F. J. RADMER, A. HALvERsoN. 

